Abrasive machine of the rotor type



Sept 22 1942- L. ILLMER ErAL 2,296,615

ABRASIVE MACHINE OF THE ROTOR TYPE ou/s /LLMEQ VERMaN fi PIM/ HS SePf- 22, 1,942. A L. ILLMR E'rm. 2,296,615

ABRASIV MACHINE OF THE ROTOR TYPE Filed Jan. so, 1941 :s sheets-sheet 2' INVENTORS: Low: /L LME/F BY fmt/55N l?. PHL'. 17s

Sept. 22, 1942. lLLMl-:R Erm.. 2,296,615

ABRASIVE MACHI-NE 0F THE ROTOR TYPE Filed Jan'. 3o. 1941l 3 sheets-sheet 3 IMs nl HG. 3A

INVENTORS.' oa/s ,/L Mer BY l/E/f/va /v Pm is @will Ik 69 Patented Sept. 22, 1942 ABRA'SIVE MACHINE OF THE ROTOR TYPE Louis lllmer and Vernon R. Pallas, Cortland N. Y.; said Pallas assignor to Leota T. Pallas Application January 30, 1941, Serial No. 376,646

1i) Claims.

The present invention broadly relates to the art of surface finishing equipment and more particularly pertains to an improved rotary type of abrasive machine comprising single or multiple drum-shaped rotors spacedly carried in tandem upon a common drive axle and of which rotors the respective skirt components are each separately embraced or perimetrically sheathed by abrasive tape means to constitute a substantially endless cutting agency in grinder Wheel fashion. Each such rotor housing may be parted axially into counterpart drum components, being preferably split into semi-cylindrical shoe sections and arranged as a demountable unit to compactly stow therein a surplus supply of tape Vthat can readily be renewed without having to dismount the rotor drive axle from its pedestals. Confined between the rotor head walls of each drum section, is a pair of spindles that may respectively mount a supply spool and a takeup spool. Roll tape of iinite length may have its opposed ends secured to the respective hubs of such mated spools with a medial active t'ape region threaded exteriorly around a corresponding rotor shoe. Means have been provided either to intermittently renew the spent shoe embracing tape or to continuously feed the roll tape off the supply and on to the takeup spool in unison with the drum rotation.

Mated sectionalized shoes are operatively assembled into a balanced rotor capable of carrying its tape sheath at high peripheral speed with a resulting rapid cutting action for a given tape grit. In our intermittently renewed exemplification, provision is made to quickly advance a virgin length of stowed tape into its active drum embracing zone and thereby manually replenish a leading spent tape portion as needed. Compensating means have also been provided to longitudinally tension the renewed tape and for maintaining such tension against slackening.

When grinding a wide plate of metal or wooden stock it is expedient to work with manifold tapes that are respectively kept narrower than the overall plate width. Such compact'side by side tape application facilitates a uniform and commercially complete utilization of all available grit, whereas the use of corresponding single tape Width tends to distort and otherwise becomes unwieldy to handle eifectively. In order to obviate any cutting gap between such several tapes, certain contiguous longitudinal edges are given a slight overlap to cooperatively bring about a streakless nish over the entire treated plate width.

In the present instance, treated strip or sheet product may be passed at a slow traverse beneath a rapidly rotating drum, the allowable depth of cut being in part determined by the tape grit, its applied contacting pressure and rate ofproduct traverse. After the surplus tape supply has been exhausted, the respective split units of our several rotor assemblies may be individually disjointed and have a renewed supply of tape installed therein without removal of the drive axle. The independent radial withdrawal 'from the axle of such rotor sections constitutes a significant feature of the present invention. The journalled axle ends are floatingly mounted to compensate for normal variations in tape or product thickness. In addition, said axle end regions may be equipped with pneumatica'lly controlled loading means that simultaneously thrust the active drum tape toward its treated plate.

The object of our invention is to devise vapparatus of the indicated character capable of cooperatively utilizing manifold abrasive tapes for combined intensive pregrinding or polishing of a treated product on a low cost output basis. Embodied herein are also other structural refinements that promote the end in view. particularly to allow of independently servicing any one rotor unit with a renewed roll tape supply when said rotors are kept closely spaced in axial tandem along a common drive axle.

The present specification is descriptive of a machine analogous in. certain respects to the teachings set forth in our copending application, Serial No. 372,242 as filed Dec. 30, 1940.

Reference is had to the accompanying three sheets of drawings which are illustrative of alternative embodiments, and in which drawings:

Fig. 1 is a top View of an abrasive machine equipped with manifold tape carrying drums.

Fig. 2 represents an elevational end view as seen from 2 2 of Fig. 1, While Fig. 3 shows a cross-sectional drum assembly taken along '3 3 of Fig. 1.

Fig. 3A fragmentally shows a certain quadrant of Fig. 3 but using a diierent kind of roll tape.

Fig. 4 presents said drum assembly taken along the angular part line 4 4' of Fig. 3.

Fig. 5 is a drum end view as seen along 5 5 of Fig. 1, while Fig. 6 details an axle journal mounting taken along 6 6 of' Fig. 1.

Fig. '7 illustrates in plan a modified drum embodiment, and Fig. 8 is an elevational view'thereof taken-along 1ine88 of Fig. 7-.

jmay be resorted to.

Fig. 9 fragmentally depicts a portion of the Fig. 3 assembly but equipped with a composite abrasive tape.

Referring rst to the Figs. 1 to 6 disclosures, a preferred type of our machine may comprise a skeletoni'zed horizontal framework including laterally spaced stationary pillow blocks such as I and II that may be interbraced by any suitable tie bar means such as I2. These pedestals may carry relatively stiff mated drive axles I4 and I5 `therebetween in the similar journal boxes I6 and Il. An interposed lay shaft I8 may be mounted in conventional bearings such as I9. Corresponding axle ends may be driven in unison by the meshed spur gear 2i) mounted on the lay shaft. A sprocket 2l may be chain driven from an electric motor to rotate the drums at a peripheral velocity of several thousand feet per minute.

Spaced along the respective axles in staggered endwise relation as shown in Fig. l, are manifold built-up rotor drum assemblies such as 22 and 23 which may be multiplied to any desired extent. The perimeter of each rotor may be snugly sheathed by the paper backed abrasive tapes 24 and 25 having a width'W. The respective 'longitudinal tape edges of next adjacent rotors are disposed in slightly overlapping registry designated by the letter L. Collectively said several tapes may be made to cooperatively span the overall width X of the treated platelike Astock or abraded product 26 without leaving any intervening ungro-und ridge in the finished face.

Referring to Fig. 3, a laterally stiff platen 21 may underlie such product and be yieldingly upheld upon a rubber support such as 28 to 4compensate for abnormal variations in the run 'of product thickness. If desired, the platen may also be made bodily adjustable for a change in height. In the case of treating thinly rolled strip stock, such metal product may be reeled longitudinally through our machine at a relatively slow rate of traverse. When treating a flat faced wooden product, a traveling platen As will be understood, the bridge bar I2 is intended to be raised above the xed Vbasal level of the pillow blocks to freely lclear the treated product.

As regards the structure of our built-up rotor,

may comprise a sectionalized drum to include two or more housing counterparts or the like mated metal shoes 3U and 3I that are separable along a split o-r parting face such as 32. Each shoe section is preferably provided with a semi-cylindrical skirt forming component 33 -having laterally spaced head components 34 and 35 to constitute a hollow housing unit that is bodily demountable along the dowelled split face V32. These assembled skirt components conjointly vcomplete a cylindrical tube of which the perimeterV runs truly concentric with its drive axle. Opposed exterior head anges 36 and 31 (see Fig. 5) may be clamped together by the bolts 45 to firmly mount the drum sections in place about its axle. The axle dowels 38 retain the assembled drums in spaced tandem relation.

Spanning each pair of semi-circular head walls 34 and 35 `are complementary spool spindles 39 and 40. A supply spool 4i has a strip of surplus roll tape 42 (preferably paper backed) stowed ,upon the spool hub; said hub may be keyed to one such spindle as in Fig. 4. The inner tape end may be affixed to such hub by stick pins 43 or the like attachment. A resilient drag clip 44 may frictionally retain the supply spool against unwanted rotation. If desired, our tape strip may also be given an equivalent form of vernation.

Referring to Fig. 3, a mated takeup spool 46 may have the other roll tape end reversely mounted thereon. A medial active tape region 49 may 4be snugly threaded over the rubber rimmed guide rollers 41 and 43 respectively located closely adjacent to the terminal regions of the split face 32, the abrasive being faced outwardly and sheathed exteriorly around the perimeter o-f the corresponding arcuate skirt 33 as shown.. A guide vane 53 may be clampingly interposed between corresponding ange ends to serve as a flush inset ller that perimetrically completes the space between contiguous rollers and non-,retractibly backs the exposed tape throughout the active length thereof. In adidtion, it is preferred to groovethe drum perimeter and afxedly cement therein a strip of backing felt 5I by which to retractibly cushion the tape against tear and allow for lack of uniformity in tape thickness when brought into operative engagement with a rigid treated product.

For the purpose of tensioning the ejected active 'tape region 49, corresponding spool spindle ends may be equipped with independent and reversely disposed ratchet wheels 52 and 53 (see Fig. 5). Loosely centered on each such spindle is a shiftable follower plate 54 or 55 that may each pivotally mount a spring retained pawl 56 and be provided with a stop tit 5l. Interposed dual thrust prongs 58 and 59 tend to rotate said plates around their respective spindles toward the spread positions indicated in dotted outline which brings the stop tits into abutment with the secured foot region of said prongs. Increased tensioning of the exposed tape length 49, springs said prongs toward each other. Plural Wrench holes 6U in each ratchet wheel permit the supply and takeup spool spindles to be manually rotated in reverse directions until a proper active medial tape region becomes tightly stretched in place about the felt 5I as a semi-rotor sheath. The resilient prong thrust thereupon automatically follows up the ratchet pawls to compensate for any diiTerences in moisture absorption, expansion or other physical characteristics between the abrasive tape and its embraced metallic drum skirt. The applied active tape is thereby maintained in a taut condition irrespective 0f atmospheric conditions or drag stretch. In order to replenish a spent active tape length, a retractible pawl finger piece 6I may be manipulated to release one of the ratchets. By advancing the tape supply, a renewed virgin tape length 49 may readily be shifted into place stepwise, all without having to disrnount the rotor axle or dismantle the drum shoe sections. The described assembly supplies a comparatively large surplus of stowed virgin tape far longer than is normally afforded in the case of a conventional endless abrasive belt for similar duty. In Fig. 3, the tape of a fully loaded supply spool has been partially transferred to its takeup spool.

When our rotor is utilized as a floor sander or the like in which coarse grinding is initially required and then followed up by successively finer grits, such need may be met by the modied single tape roll shown in Fig. 3A. This supply roll comprises a series of graded grits in assorted tape lengths 42', 42, etc., respectively having afixed overlapping ends to constitute a continuous strip of which a selected portion may be rolled into the active shoe position 49'.

After successive advances have exhausted the surplus tape carried by the sup-ply roll, the bolts V45 may be unfastenedl to allow each assembled rotor section to be individually removed from its axle as a unit for servicing. 'The long spindles 39 and 'le thereby become cleared for unobstructed withdrawal. A reloaded pair of supply and takeup spools may be conveniently serviced into such housing unit at the minimum of labor cost although a series of rotors may be installed in close tandem relation. Paper backed roll tape suflices for present needs, this being considerably cheaper to use than fabric backed tapes commonly required in making up endless abrasive belts.

Any suitable style of axle bearing may be employed but it is preferred to resort to the floating type detailed. in Fig. 6. Here a squared journal block 62 is slidably guided betwen spaced pedestal jaws such as 63. Interposed spring means 64 of the adjustable type, may resiliently uphold said block. A tubular bearing cap 65 houses therein a metallic bellows or the like sealed diaphragm 69 which loads the rotor axle in a counteracting relation to said spring means. A branched lead pipe 6'! may convey actuating fluid to said bellows at each axle end. By suitable control of the iluid pressure, the rotors may be manually raised or lowered. with respect to the treated product; such control also serves to adjustably regulate the applied tape contact pressure.

Our nice drum adjustment enables an operator to closely follow up for a change in tape grit thickness or its gradual reduction by wear. An adjustable stop prop SAA may be placed beneath each block 52 to provide for a set clearance gap Sli-B that limits the cut depth for such abrasive ruins. The lower shank BilC of such threaded prop may be splined and have a slip bevel gear GfD mounted therearound. A meshing gear 66E may be selectively actuated through the worm gear 68A provided with a graduated dial 68B. The manipulative transverse worm shaft 69 simultaneously adjusts corresponding gear dials to hold the bridging rotor axle at a prescribed level in planar cutter fashion. Said stop props restrict the tape penetration and assure a level abrasive cut irrespective of an original undulous profile on part of a treated surface. A dial pointer 68C visualizes the prevailing clearance gap 64B and thereby fixes the allowable cut depth. When the retractible blocks 62 rest upon their respective props, said axle remains free to yieldingly lift against diaphragm pressure.

Turning now t the alternative embodiments shown in Figs. '7 and 8, the single split rotor 10 thereof is essentially similar in structure to the l Fig. 4 exemplication except that the ratchet gear is now replaced by a modied spool drive adapted to continuously advance the tape from a supply to a mated takeup spool. To this end, a pair of pillow blocks 1| and 12 may each be provided with a centralized bearing 13 including a floating journal block of the kind represented in Fig. 6. A rotor axle 74 spans these journal blocks and is intended tobe power driven through the sprocket 'l5 or the like. Said pillow blocks may also mount therebetween a primary gear shaft 16 and a differential gear shaft 'H disposed in parallelism with the rotor axle.

Corresponding overhanging ends of the takeup spool spindles i8 and T9 may respectively be equipped with a planetary system of rolling gears 80 and 8| that oppositely mesh about the restrained intermediate gear 82. The last named gear has affixed thereto a driven gear 83, both being loosely mounted upon said axle. A drive gear `84 carried by the differential shaft "1.1. may mesh with the gear 83 as in Fig. 7.

Afxed to the axle is a spur gear 85 which drives the mated gear 86 on the primary shaft 1.6. The speed ratio of the gears 83-134y and 535-86 is preferably kept to a one to one relationship. Interconnecting the shafts I6 and 'FI is a train of change gears which may comprise twin gear pairs such as 88-89 and Sill-9| of which the interlocke-d gears B9 and 90 may be loosely mounted upon the other end of the rotor axle T4, as shown. Such gear train is disposed to drive the differential shaft at a speed slightly different from the primary shaft in order that the respective -fed shoe tapes 93 and 94 may be slowly advancedl from their respective supply spools on to a mated takeup spool.

For example, the gear 89 may contain an extra hunting tooth over the gear 38, such for instance as 57 versus 56 teeth while the gear 9| is provided with 56 teeth that mesh with 55 teeth in the gear 99. Such set-up requires more than 3000 axle revolutions to bring about a single spindle turn. By the substitution of other change gears, the differential speed may be progressiv-ely altered to suit various t-ape grits and treated material. The exposed partially spent tape portions such as 49 may thereby be continuously renewed to maintain the mean effective cutting capacity of our rotor at a substantially constant rate throughout the tape life Without requiring any periodic longitudinal shift as in Fig. 5.

For tape reloading purposes, the split rotor 'i9 may be conveniently `dismounted in semi-cylindrical or the like counterpart units. The convolutions of the initial roll tape supply may be restricted to keep its feed rate comparatively constant as the takeup spool builds up with tape. A more uniform tape advance may be had by mounting the gears 8B and 8| upon certain of the spool spindles through -a frictional slip connection (not shown) and interconnecting each such dragged planetary gear to run in mesh with an intermediary gear such as 95 (schematically shown in dotted and dashed outline in Fig. 9). One of the guide rollers 41 or 48 will then be positively actuated as a driven feed roller to advance one of the tapes such as 93 or 94 at a uniform rate of feed irrespective of the prevailing roll size of the take-up tape.

When regularly fed, the accompanying frictional Adrag off-ered by the exposed active tape length may be materially eased by the use of a composite tape as in Fig. 9. Her-e a paper or fabric backed abrasive tape 91 is further backed by a supplementary thin strip of metallic foil 98 that may be cemented in pla-ce. When the felt strip 5| of Fig. 1 is eliminated, such antifriction foil may bear 4directly upon the metal perimeter of the split rotor skirt to facilitate tape slip, particularly when lubricated. The cushioned platen support 23 or the floating axle journal block 62 would still function to compensate for irregular product thickness. If desired, our composite tape may also have a thin layer of felt interposed between its dual backing components 97 and 98.

It will be apparent that the single Fig. '7 type of rotor may be collectively assembled in the Fig. 1 fashion; also that a single motorized unit of either rotor type may be mounted upon a dolly or truck platform for floor sanding purposes or the like bodily portable needs. All components of our high speed rotor `assembly are ldisposed to maintain a substantially perfect balance about 'the axis thereof. A pair of such rotors may be utilized as a centerless grinder for supercially polishing metallic wire.

The foregoing disclosure will, it is believed, make apparent to those skilled in this art the more outstanding commer-cial advantages and improvements afforded over the prior grinder art, it being understood that we reserve the right to modify the specifically disclosed structural features of our illustrative embodiments, all without departing lfrom the spirit and scope of our invention heretofore Idescribed and more particularly characterized in the appended claims.

We claim:

l. An abrasive machine comprising an axially split hollow rotor assembled from plural skirt forming sections abuttingly amxed around the rotor axis to complete a cylindrical profile, contiguous perimetric end regions of said sections respectively having tape receiving gap means therethrough and which sections when disconnected are radially separable from each other, and a strip of abrasive tape of finite length of which a medial length is actively applied to sheathe one such skirt section and leave opposed appended strip ends that are respectively entered through next adjacent section gap means to stow a surplus supply of tape within the skirt confines.

2. An abrasive machine comprising a pair of i laterally spaced axles, drive means for simultaneously rotating said axles, a cylindrically hollow rotor mounted on each such axle in staggered relationship, each such rotor being assembled from plural skirt forming sections abuttingly affixed around the axle thereof and of which sections contiguous perimetric end regions have a tape receiving gap therethrough, and a strip of abrasive tape carried by each such skirt section and which tapes respectively include a medial length region actively applied to sheathe one skirt section in the rotor thereof and leave opposed appended strip ends, next adjacent longitudinal tape edges of said staggered rotors being cooperatively disposed in overlapping registry and said opposed strip ends thereof being entered through their respective section gaps to stow a surplus supply of tape within the corresponding rotor contines.

3. An abrasive machine comprising a driven drum-shaped rotor assembled from hollow semicylindrical skirt forming sections concentrically affixed around the rotor axis and which sections are separable along a parting face lying in substantial parallelism with the rotor axis and respectively have tape receiving gap means disposed contiguous to the terminal regions of said face, a rotatable supply spool and a takeup spool inbuilt within the connes of one such section to constitute a self-contained independently demountable unit therewith, and abrasive tape of nite length whose opposite end regions are respectively coiled about said supply spool and about its take up spool with an intermediate tape length carried outwardly through correlated gap means to exteriorly sheathe the skirt of said one section, the last named section together with its spools being radially withdrawable as a unit from the other section for tape reloading purposes.

4. An abrasive machine comprising a driven hollow drum-shaped rotor assembled from a plurality of demountably interconnected skirt forming sections having radial faces abuttingly afF fixed to complete a cylindrical profile around the rotor` axis and contiguous perimetric ends of which abutting sections respectively have tape receiving gap means therethrough, a guide vane interposed between next adjacent faces and having Va ller edge that lies in substantial flush alignment with said proiile, and a strip of abrasive tape including a medial active length portion operatively applied to sheathe one skirt section and leave opposed appended tape ends entered through certain of such section gap means for stowage wholly within the rotor conines.

5. An abrasive machine comprising a hollow drum-shaped rotor assembled from a plurality of split skirt forming sections abuttingly disposed around the rotor axis and contiguous perimetric end regions of which sections have tape receiving gap means therethrough, and a continuous strip of abrasive tape provided with graduated grits in assorted strip lengths and which lengths are arranged to successively sheathe one such skirt section and leave opposed appended tape ends that are respectively entered through certain of said section gap means for stowage within the rotor confines.

6. An abrasive machineincluding a driven axle, a cylindrically hollow rotor mounted upon said axle, floating dual journal blocks respectively mounting opposed axle ends, resilient ineans thrusting said blocks in a direction perpendicular to the axle length, and fluid actuated diaphragm means for controllably exerting pressure counterwise to said resilient thrust. l

7. An abrasive machine including a driven axle, a cylindrical rotor mounted upon said axle and the perimeter of which rotor is operatively sheathed with abrasive tape, floating dual journal Yblocks respectively mounting opposed axle ends,

resilient means thrusting said blocks in a direction perpendicular to the axle length, iiuid controlled diaphragm means for regulatably exerting pressure counterwise to said resilient thrust, and adjustable stop prop means selectively setting the allowable floating shift of the respective 8. An abrasive machine including a driven axle, a cylindrical rotor mounted upon said axle and the perimeter of which rotor is operatively sheathed with abrasive tape, floating dual journal blocks respectively mounting opposed axle ends, resilient means thrusting said blocks in a direction perpendicular to the axle length, Vfluid actuated diaphragm means for controllably exerting pressure counterwise to said resilient thrust, adjustable stop prop means for each such block limiting the allowable floating shift thereof,

and interconnecting mechanism for simultaneously adjusting said stop prop means.

9. An abrasive machine comprising a sectionalized rotor housing mounted on an axle and equipped with a hollow cylindrical skirt component axially split by a parting face, means for driving the axle, dual roller means respectively located in parallel alignment with said axle and contiguous to each diametrically opposed region of said face, a surplus supply of abrasive tape carried interiorly of the rotor confines and a portion of which tape is threaded over said dualroller means in a cylindrically sheathing relation to the corresponding skirt portion interposed therebetween, gear means operatively interconnecting one such roller means with the axle to positively and continuously advance said sheathed tape and which gear means includes a train of differential change gears,

10. An abrasive machine comprising a driven being backed by a strip of metallic foil interposed between said tape and the sheathed skirt portion, and actuated feed means slippingly advancing the tape longitudinally in a direction outwardly away 5 from said gap.

LOUIS ILLMER. VERNON R. PALLAS. 

